LOOPER TECH TIP's.........

[frederick55]

Gary, I enjoy your reading and projects. That said will the engine run on 100% seafoam? I'm thinking of doing that on my 300xs at idle to keep the injectors clean and carbon free rings.

Add one quart of Seafoam to three quarts of gasoline, and don't forget the oil! Run one or two gallons of this mix at idle, revving occasionally. I've picked up 7-9lbs of compression from freeing up the rings doing this, which I do whenever a compression check looks low. Works like a dream. Great post Gary! I'm in the process of going through a '98 225 looper right now, and this gives me a few MORE things to pay attention to.

[Instigator]

Forgot about this thread and just stumbled upon it again.

Here's one I just did after popping one of my Sonic motors due toooooooo......, wait for it.........., DETONATION
Guess which hole too..............................?????????????????? #2.
I think I've now popped 4 of my p.heads since we've been down here (7 yrs) in Fla. All four from detonation, and all four #2.
Matter of fact, I think every popped motor I've bought down here ( 20 or 30) has lost #2.

The Sonic motors are pig fat rich and still knocked the skirt off a piston. I knew I was on the edge w/compression vs octane and since I don't listen to anyone else.......

Anyhow, heres the cooling mod very similar to what I did to the 3.3 mod motor and don't think I posted pix's of it. This is one of the Sonic motors and I've now done the mod to both.

In the completed picture you have to look close to see the hoses behind the coils. I like keeping my motors stock appearing.
I pulled the hoses with the motor running and I'm getting a steady flow of water (from hose and block) at idle. What my read is, is that after a mid/high speed blast, when you back off, the water pump slows down and the tops of #2 uncover from cooling water. These motors already run way lean at mid range, so the combustion chambers are already hot,, uncover the tops of the cylinders and powie!

Funny thing too. was looking at a 3.3 p.head base gasket and I think it reverses cooling flow compared to the 3.0's. I know I tested both on the 3.3 and ended up w/the 3.0 gasket but I think only after doing this mod. The gasket may do it. Course you then have to pull the p.head to install it.

So now the question is, do I have the stones to run these motors again on the same octane to accurately test the effects of my mod's Serious doubts..

Bottom of block at exhaust.



Top of block. (both are 1/8" npt by 1/4" hose barb)



Completed.

[frederick55]

Am I seeing that you have tied back into the bottom of the exhaust from the top of the block? Thought about doing something similar, but I was going to have the two at the top going to telltales so I could see what was going on on each side. Does your way help maintain pressure or is it a free drop into the exhaust?

[powerabout]

If you want to see if you have fixed anything, run clear plastic hose into the cockpit, make plenty of coils and then overboard.
Its very easy to see if there are air bubbles in the line when you are driving ( or the co -pilot)
Same test for engine too high, you can have pressure but its made up of air and water, air doesn't cool so well.

[racer]

Gary, the issue I see here is the water at the bottom is in coming and at the point you put it back in is right before it enters the thermostat so you loose some water flow to the ctr of the block which can lead to the exhaust runners pushing on the liner and a cyl going out of round when warm. What I find works good is to add a hole from the water cavity next to each top cyl into the exhaust cavity. That supplies more water to the top without a lose around the runners. #1 is the first to loose water as it is the highest #2 is the first to break due to an exhaust tunning issue, when jetted the same that cyl exhaust temp is right at 100 degrees hotter with the probes in the ctr of the port. Remember the V8 uses the same pump and they are prone to #3 and 5 not the top. I would use the 5001595 pump kit on Mod engines as it does not have a bleed hole and puts out a bit more water.

[baja200merk]

Gary you had a 3.3 gasket on the 3.0 I had why are you running 3.0s on your engines?

[Instigator]

fredrick, bottom nipple connects a hose to the top one. The blocks fill from the bottom first and the heads are the last thing to get water.

powerabout, great idea.

Al, thanks for the info. I thought of that but didn't have the time to figure out where to drill and the 2nd motor was still assembled. Also, top 2 holes on both motors were already one notch rich.

Kevin, I don't think that motor had a 3.3 gskt on it when I built it. Been enough yrs ago I could be wrong but don't think so. They had it apart at least once while it was up there and have no idea what was done.

[baja200merk]

That's right forgot. Well it had one when I pulled the power head. I Wonder if it was intentional.

[Instigator]

Have gotten a couple pm's asking about this one, in that it offers a couple views/options to the same issue.

First off, Al's forgotten more than I'll ever know but the only way you learn is by trying what your told won't work.

On my 3.3 hot rod motor, we felt it was actually steam which then builds pressure that then prevents/slows the cooling water from covering the top of the jugs. On that one I basically just vented the top of the block into the dump hoses w/o attempting to introduce additional cooling water.

That boat was much lighter loaded than my current Sonic is which changes things. I also have a different opinion on whats happening too.

We know the V loopers are prone to be lean in the mid range to start with. Then if you do a blast and back off, into that lean mid range......, the cylinders are over heated due to previous extreme loading and then reduced cooling flow (as well as fuel). Now add to the situation that the motor may have more compression and....., pop.

I actually got to thinking this may be part of the issue when riding on a neighbors twin looper V-6 27' fische bote and we were testing a repair I'd done to one motor w/a p.head I'd built him several yrs previous.
Against my warnings the owner was doing hole shots, from neutral to fire wall, stop, repeat. Rig was probably 10K+ lbs. So he's putting the motors under full load,to zero load, no fuel for cooling and slowing the water pump down which IMO, then reduced the cooling water to the block and pop!
Owner knew what he did as soon as it happened.
And, you could hear it pop on decceleration so after coming off full load. We were actually coming off plane when it popped.
He freaked and I verified what he thought. I told him to pull the cowling and look at the front of the block and you'll see a hole where #2. piston/rod came apart.
He did and I was right.

So my assumption was, 100% load but propped perfect, tuned to the best of my ability, new impeller, fresh gas, fresh p.head and did this?????

That's why I just did what I did to my Sonic. Course the million dollar question is: if the block was vented, would it have popped?? My opinion is yes.
I believe it was the reduction of the water from the impeller that completed the perfect storm.

Al, feel free to poke my theory full of holes ; )

Kevin, not sure.

[racer]

Like Gary I have also recieved some PM's. I respect Garys opinion its just a little different than mine.

Gary IMO if it were due to water the v8 would also loose the top cyl since they use the same pump and it has to raise the water even higher. The V8 does route water different from a closed deck 6, I have never liked the cooling path on the closed deck engines and do rework it when I do a rebuild. I will agree cooling is part (but only part) of the issue. I feel there are better more effective ways to solve the problem. Mar-Fab does the same cooling mod I do, they started it about 3 years after we developed this mod. By better controling the water direction I have found block temps to be much more even, this also helps with numbers 5&6. In stead of filling the entire block from the bottom up we fill the ctr first and then into the top of the cyl but is controlled to go down the exhaust side down to the bottom and then up around the bottom cyl to the top and out thru the thermostat. This intales plugging a couple holes and drilling new, it also means adding 3 diverters per side.

[lokinutz]

I don't know much, but would like to throw this out there... i have been lucky enough to witness and understand Al's cooling mods (I went through my block with a fine toothed comb when he did mine) and have seen how well it works. OK, let me wipe my nose off...

But, something that hasn't been discussed much in this thread is the fact that these motors will always be prone to pop like in Gary's '27 fische boat example due to the non-ratcheting lower unit. These things will be drug slowly down through the worst conditions with the ignition firing away relentlessly (at a very retarded timing since you are out of the throttle...causing it to heat the hell out of the exhaust side of the piston) as the carbs just don't deliver the fuel necessary. Combine that with the longer more efficient exhaust runners on the top two carbs, and well, we know what happens.

Gary, you are always welcome to shoot holes in my theories.

Al does it all the time, he just does it in PM's so I don't look like a complete moron!

[Instigator]

Al does it all the time, he just does it in PM's so I don't look like a complete moron!

Dude, he called me to tell me be had Frank 1 in his shop and how I could improve on my honing process

Who else does that?

Both you guys made interesting points that I hadn't considered. Thing of it is, w/o testing one change and one change only, how do you ever know for sure? You don't.
Especially w/o having a facility similar to Al's skunk works.

On my 3.3 project, I changed so much and grew so frustrated w/testing, even having a ramp and prefect location 2 mls from my house, that I'd change as many things as I could to try and speed the process up.
Of course that didn't work ; )

Thanks again for the ideas guys. Nice to still have a few people around that can make you put on your thinking cap.

[powerabout]

IMHO When tinkering to solve a problem you need to accomplish a few caveats;
1. tests have to be repeatable
2. you need to prove your theory's right and or wrong

Getting a positive result may just be masking a symptom

Water flow in a block is not going to easy, just guessing but what would you need to do?
CFD model?
cut it open to try and work it out?
Make the outside of the water jackets removable like and old blocks and make the water covers out of acrylic?
calculate the heat rejection and where that is versus tempo increase and flow from various places?
cut windows and epoxy clear patches in?
drill dozens of holes and plumb them external and see what comes out where and what temp?
Have external water supply with control over tempo and pressure/flow?
Feed some water in with food dye and see where it comes out ( assuming you made a few extra outlets?)
run abrasive in your external water supply and see the wear pattens inside the engine?

Sounds like I have a project when I retire
A dyno sure helps with repeatable conditions
Cheers

[Instigator]

For the guys pm'ing me asking for head spec's. I did a story on here a while back w/pix's and specs and can't find the damn thing so this will have to do until it re-surfaces.

Could only find two pix's as of now.

#1. is the OEM 2.7 head. As Al has educated us on many times for many years, this head came in two chamber depths depending on motor.
.675" for XP/GT/225 and .700" for everything else. Same heads other than that.
The combustion chamber design is much larger but shallower than the late model deep pocket but the big difference is the taper leading into the chamber. There is much written about how this should be done re. application. Width and angle change what it does and how.
Much debate has been done, many differing opinions and I'll leave that one up to you.



#2. This is a the late model deep pocket head after some modifications I do to them. Has the above mentioned taper (same as above other than angle and width ; ) ) aiding in squish control and has a TON decked off of them to get compression where it needs to be.
I will state right here that Al does not like the decking part as he feels removing this much meat also removes the heads abilities to dissipate heat which then promotes detonation.
I have many pistons in my garden that would side w/Al's theory but I'm still fighting that one ; )
I do this as I feel w/the smaller diameter combustion chamber it keeps the charge more centrally located to the plug and is basically a "hemi" head and therefor out performs the above.
Also gives us an option now that the 2.7 heads are becoming near unobtanium.

[powerabout]

did you ever find out if the max advance needed to be different with these 2 heads?
cheers